Actual 2025/2026 AQA A-level PHYSICS 7408/1 Paper 1 Merged Question Paper + Mark
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2
*02*
IB/M/Jun24/7408/1
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outside the
Section A box
Answer all questions in this section.
0 1 . 1 State the names of the four fundamental interactions.
[1 mark]
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2
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0 1 . 2 State the products of the decay of a free neutron.
[1 mark]
0 1 . 3 Explain which of the fundamental interactions is responsible for the decay of the
neutron.
[2 marks]
0 1 . 4 The forces between two moving electrons cause their paths to change.
Explain, using the concept of exchange particles, why the electron paths change.
[3 marks]
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*03*
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IB/M/Jun24/7408/1
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outside the
0 2 box A positive pion collides with a neutron and the following interaction is observed:
 + + 0 π →Κ + n + Σ
Σ0 is a neutral sigma particle with a strangeness of −1
The interaction can be used to deduce the classifications of the Σ0
.
0 2 . 1 Identify the classifications of each particle in Table 1.
Tick () the appropriate boxes for each particle.
[2 marks]
Table 1
Particle Baryon Hadron Lepton Meson
π+
n
K+
Σ0
0 2 . 2 A conservation rule predicts that the following interaction cannot occur:
 0 + n + Σ − − π →Κ
State the conservation rule.
Go on to explain your answer.